title: Influence of storage period and effect of different brands of acrylic resin on the dimensional accuracy of the maxillary denture base.
abstract: The aim of this study was to evaluate the dimensional changes of denture bases made from different resins after different storage periods. For this purpose, 25 sets of plaster models/resin bases were prepared using 4 acrylic resins submitted to two types of polymerization: 1--QC-20 submitted to polymerization by microwave energy; 2--QC-20 submitted to polymerization by water hot bath; 3--Vipi Cril submitted to polymerization by water hot bath; 4--Vipi Wave submitted to polymerization by microwave energy; and 5--Onda Cryl submitted to polymerization by microwave energy. After polymerization, the specimens were sectioned for accuracy readings using a comparison microscope. Readings were taken at 3 points: the crests of the right (A) and left (B) ridges, and the median region of the palate, in 4 different periods. The data obtained were submitted to two-way ANOVA and Tukey's test at 5% significance level. The greatest distortions were found in the posterior palatal region of the base (M), with statistically significant difference (p<0.05) for the studied resins. All acrylic resins presented dimensional changes and the storage period influenced these alterations.
authors.affiliation: Department of Dental Materials and Prosthodontics, São Paulo State University, Araçatuba, SP, Brazil.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Miéssi
authors.forename: Marcelo Coelho
authors.initials: MC
authors.lastname: Goiato
authors.forename: Daniela Micheline
authors.initials: DM
authors.lastname: dos Santos
authors.forename: Stefan Fiúza de Carvalho
authors.initials: SF
authors.lastname: Dekon
authors.forename: Ricardo Coelho
authors.initials: RC
authors.lastname: Okida
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D003735:Dental Casting Technique; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing; D003819:Denture Bases; D003779:Denture Design; D003827:Denture, Complete, Upper; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D008872:Microwaves; D003765:Models, Dental; D011108:Polymers / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry; D014885:Waxes
chemical_list: D000180:Acrylic Resins; D003764:Dental Materials; D011108:Polymers; C488492:QC 20 (denture base resin); D014885:Waxes; C539103:onda cryl; C539101:vipi cril; C539102:vipi wave; D014867:Water